How Caffeinated Energy Drink Triggered Teen's Heart Problem

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For a teenage boy in England, drinking one highly caffeinated
beverage at the gym set off a heart problem he didn't know he
had, according to a new report of his case.

The boy's heart began racing, so the 17-year-old went to the
emergency room, but his cardiovascular exam looked normal, as did
a chest X-ray and routine blood tests. Doctors gave him drugs to
slow his heart rate, but the medications instead caused his blood
pressure to drop and led to a state called atrial
fibrillation, making his heartbeat irregular and chaotic.

A cardiologist then gave the teenager an electric shock, which
dramatically improved the boy's symptoms and blood pressure. And
an electrocardiogram (EKG) revealed the problem: there was an
extra electrical circuit in the boy's heart. [ Heart of the
Matter: 7 Things to Know About Your Ticker ]

The human heart typically has one electrical pathway, and the
impulses travel along it through the organ's center from its top
to its bottom. But in people with a condition called
Wolff-Parkinson-White (WPW) syndrome, the heart also has another
electrical connection, along its side.

This extra circuit stimulates the heart "in a way that is not the
normal pattern," said Dr. Nicholas Skipitaris, the director of
electrophysiology at Lenox Hill Hospital in New York City, who
was not involved in the boy's case.

Symptoms of the condition include light-headedness, dizziness
or feeling faint, but the most common sign is rapid heartbeat.
"People can say, 'My heart is beating out of my chest," or 'I
feel my heart beating in my throat,'" Skipitaris told Live
Science.

In some people, the extra circuit is so weak that the condition
doesn't cause any real problems. People who do have problems
usually discover they have the condition during adolescence, and
have it treated before adulthood, Skipitaris said.

The extra pathway means that the heart muscle may not always
contract downward as it should, and push blood from the upper
chambers toward the lower chambers. "It can conduct upward too,
from the lower chambers back up," said Dr. Mohan Viswanathan, a
cardiologist with Stanford University’s Cardiovascular Medicine
Clinic, who was also not involved in the case.

People with WPW syndrome often don't show symptoms, but
stimulants can easily drive up their heart
rate. In the boy's case, the energy drink likely caused the
heart palpitations, but the condition can also be triggered by
dehydration, weight loss drugs that increase adrenaline or taking
cocaine, Viswanathan said.

About 1 to 3 people per 1,000 people have the syndrome. Less than
0.6 percent of people with the syndrome are at risk of sudden
cardiac death, the study reported.

After learning that he had WPW syndrome, the teenager underwent
several electrophysiological studies and then surgery to turn off
the extra circuit in his heart.

"It's like taking a wire you don't want to function anymore, and
cutting it so the wire can no longer conduct electricity,"
Skipitaris said.

In the 1960s and 1970s, people with WPW syndrome underwent
open-heart surgery. These days, the procedure is less risky, and
involves slipping a thin tube called a catheter into the heart
through a vein in the groin. The catheter delivers radio
frequency waves that deaden or cauterize the area with heat,
Viswanathan said.

"It usually takes less than 20 seconds once we get to the right
spot," Viswanathan said. "Low and behold, the moment it's gone,
the EKG changes into a normal EKG."